Add a the common code used by all PXA variants.
This is the first step in the transition from architecture defined
clocks (in arch/arm/mach-pxa) towards clock framework. The goal is to
have the same features (and not all the features) of the existing
clocks, and enable the transition of PXA to device-tree.
All PXA rely on a "CKEN" type clock, which :
- has a gate (bit in CKEN register)
- is generated from a PLL, generally divided
- has an alternate low power clock
Each variant will specialize the CKEN clock :
- pxa25x have no low power clock
- pxa27x in low power use always the 13 MHz ring oscillator
- pxa3xx in low power have specific dividers for each clock
The device-tree provides a list of CLK_* (ex: CLK_USB or CLK_I2C) to get
a handle on the clock. While pxa-clock.h will describe all the clocks of
all the variants, each variant will only use a subset of it.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
